It is well known in the consumer products such as pharmaceutical, personal care (excluding oral care compositions), as well as household care applications to formulate products that provide useful characteristics such as cleansing, cleaning protecting, and benefiting, depositing and moisturizing, and firming, conditioning, providing occlusive barriers, tinting and providing emolliency. In these consumer products water-soluble polymers are used as rheology modifiers for the final compositions. Polysaccharide derivatives such as cellulose ethers, and polygalactomannan and polygalactomannan derivative products are among the best known polysaccharides for use as rheology modifiers in these applications.
Water-soluble polymers are heavily used in a variety of consumer products. Despite their environmentally friendly and biodegradable advantages, they suffer from the tendency to form lumps when in contact with water and take much longer to dissolve. Dissolution, by definition, is a loosely used term. In this case, dissolution is used to represent the two steps by which polymers go into aqueous solutions. In the first step, the polymer is dispersed into the aqueous solution. The time it takes the polymer to disperse is subject to a good deal of variability. Dispersion could be as short as few seconds or as long as several hours depending on technique, instrumentation, morphology and surface chemistry of the polymer. After the polymer is dispersed, the polymer undergoes a hydration step. In this step, polymer chains loosen up and expand their hydrodynamic volume occupying the whole solution and building up viscosity on the way. As soon as polymer molecules contact water, they tend to swell very quickly and get in contact with neighboring particles. They glue together and form lumps of various sizes that tend to delay their hydration time significantly. Good dispersion is a prerequisite for minimal lump formation and ultimately quick hydration in final applications. In all systems of water-soluble polymers, lump formation is considered a rate determining step for total dissolution time.
U.S. Pat. No. 5,869,029 discloses compositions comprising water-soluble or water-swellable polymers agglomerated by treatment with polyols, and the use of these compositions in making toothpastes. The polyols of use in this composition are selected from the group consisting of sugar alcohols, glycerol, polyethylene glycol, propylene glycol, and mixtures thereof. This composition is of utility for producing toothpaste formulations.
U.S. Pat. No. 6,258,342 discloses the use of water or aqueous polymers agglomerated water-soluble or water-swellable polymer in oral care compositions. The oral care composition or dentifrice described in this patent contains abrasives, humectants, and water-soluble polymers.
In consumer products and especially in the personal care industry, there is a safety concern regarding presence glyoxal in formulation ingredients. Currently many hydroxyethylcellulose products (HEC) such as (Natrosol HEC, available from Hercules Incorporated) and hydrophobically modified hydroxyethylcellulose products (HMHEC) (Polysurf® 67 HMHEC available from Hercules Incorporated) are surface treated with glyoxal for ease dispersion by formulators. Glyoxal-free easily dispersable polymers offer an opportunity of easily incorporating these materials into consumer product formulations for use in personal care and, household care applications where there are concerns regarding the presence of glyoxal in the formulations.